<template>
  <view>
    <!-- 自定义搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="container">
      <!-- 左侧视图区域 -->
      <scroll-view class="left-box" scroll-y :style="{height: wh + 'px'}">
        <block v-for="(item, index) in cateList" :key="index">
          <view :class="['left-view', index === active ? 'active' : '']" @click="activeChange(index)">{{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧滚动视图区域 -->
      <scroll-view class="right-box" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
        <view class="right-view" v-for="(item2, index2) in cateLevel" :key="index2">
          <view class="right-view-title">/ {{item2.cat_name}} /</view>
          <view class="right-view-list">
            <view class="right-view-item" v-for="(item3, index3) in item2.children" :key="index3" @click="gotoGoodsList(item3)">
              <image :src="item3.cat_icon"></image>
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        wh: 0,
        cateList: [], // 一级分类
        active: 0, // 被选中项索引
        cateLevel: [], // 二级分类
        scrollTop: 0
      };
    },
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      // 可用高度 = 屏幕高度 - navigationBar高度 - tabBar高度 - 自定义的search组件高度
      this.wh = sysInfo.windowHeight - 50
      this.getCateList()
    },
    methods: {
      async getCateList() {
        const { data: res } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        this.cateLevel = res.message[0].children
      },
      activeChange(index) {
        this.active = index
        this.cateLevel = this.cateList[index].children
        this.scrollTop = this.scrollTop ? 0 : 1
      },
      gotoGoodsList(item3) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      },
      gotoSearch() {
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
    }
  }
</script>

<style lang="scss" scoped>
  .container {
    display: flex;

    .left-box {

      width: 120px;

      .left-view {
        line-height: 60px;
        background-color: #f7f7f7;
        text-align: center;
        font-size: 12px;

        &.active {
          background-color: #fff;
          position: relative;

          &::before {
            content: ' ';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #c00000;
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
          }
        }
      }
    }

    .right-view {
      .right-view-title {
        font-size: 12px;
        font-weight: bold;
        text-align: center;
        padding: 15px 0;
      }
      
      .right-view-list {
        display: flex;
        flex-wrap: wrap;
        
        .right-view-item {
          width: 33.33%;
          margin-bottom: 10px;
          display: flex;
          flex-direction: column;
          align-items: center;
          
          image {
            width: 60px;
            height: 60px;
          }
      
          text {
            font-size: 12px;
          }
        }
      }
    }
  }
</style>
